Cognomen กูลศักดิ์ (กูลศักดิ์ 
) , in the world, is an extremely rare surname. The family name กูลศักดิ์ is habitual in South-eastern Asia, particularly Thailand, where it is an extremely rare surname. More frequently, กูลศักดิ์ is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| กูลศักดิ์ | Thailand |